The inventive subject matter described herein relates to integrated circuit devices and, more particularly, to input buffers.
An input buffer may be used to receive data provided to an integrated circuit from an external system. The input buffer may protect semiconductor devices in the integrated circuit from high voltage. The input buffer may have tolerance against a noise included in an input through a series of inverter stages or a Schmitt trigger.
As a degree of integration of integrated circuits increases, low-voltage semiconductor devices, such as medium-gate oxide semiconductor devices, may be preferred for use in integrated circuits. Medium-gate oxide semiconductor devices may consume less power and operate at high speed. However, medium-gate oxide semiconductor devices may be driven with a low voltage. If a voltage difference between nodes of a medium-gate oxide semiconductor device exceeds a prescribed voltage, the lifetime and stability of the device may be reduced by gate oxide breakdown or punch through. An input/output interface of the integrated circuit may support a relatively high voltage input signal for compatibility of the integrated circuit with external devices. Accordingly, there may be a need for techniques for interfacing such a high voltage input signal to a low voltage semiconductor device.